Control of crystallinity and grain structure has been a central component of advanced materials engineering and metallurgy for centuries, ranging from forging of ancient Japanese katana or swords (Non-Patent Literature No. 1) to modern nano-engineered transistor gate electrodes (Non-patent Literature Nos. 2 and 3). Mechanical, optical, magnetic and electrical properties (to name a few) can all be tailored via control of parameters like grain size, grain boundary precipitates, and crystallographic defect densities and impurities (Non-patent Literature Nos. 4-6). Metal-induced crystallization (MIC) is a phenomenon in which amorphous semiconductor materials can be crystallized at relatively low temperatures in the presence of appropriate metal catalysts (Non-patent Literature Nos. 7-8). MIC has been reported for a wide range of bulk materials with quite different material interactions (e.g., Ni, Al and Ag) (Non-patent Literature Nos. 9-13). Metal induced crystallization (MIC) of amorphous semiconductor materials has been extensively studied due to its applications to solar cells and field effect transistors.
The Si—Ag system has been extensively studied over the last three decades (Non-patent Literature Nos. 14-17). Notably, with 11% Si content, this binary system has a eutectic temperature around 830 Celsius degrees −845 Celsius degrees (for reference, the melting points for bulk Si and Ag are 1414 Celsius degrees and 962 Celsius degrees, respectively) (Non-patent literature No. 15). Unlike many transition metal/Si systems, the mutual solubility of Ag and Si in the solid state are negligible (Non-patent Literature No. 16), which is an important attribute. A recent study by Bokhanov and Korchagin on the amorphous-Si film/Ag particle system concisely summarizes the mechanisms governing MIC; the formation of eutectics is preceded by metal diffusion into amorphous Si with the formation of metastable silver silicide. Subsequent cooling of the system leads to the decomposition of the metastable silicide and subsequently to the evolution of polycrystalline Si and metallic Ag (Non-patent Literature No. 17).
However, to date, these studies and development have been limited to three-dimensional bulk and two-dimensional thin films.